Apparatus for working sheet metal



Nov. l0, 1942. E. sAcHsE Erm. 2,301,643

APPARATUS FOR WORKING SHEET METAL Filed Feb. 11. 1939 5 Shets-Sheet l ERNST SACHS: ROBERT Ko TIN@ LTER oksTEL di Attorneys r Nov. l0, 1942. T E. YSACH-SE Erm. 2,301,643

APPARATUS FOR' WORKING SHEET METAL .Filed Feb. 11, 1959 5 Shel'etS-Sheet 2 /n e f ERNST egg? s ROBERT oRT/NG HERMANN NCH/.KAB

' Att'orncqs Nov.'l 0, 1942. l iE. sAcHsE E-rAL 2,301,643

APPARATUS Fon WORKING sar-:m una-AL Y Filed Feb. 11, v19:59 sshegts-sheet s' Nv.1o,1942. www; lEem; 1 2,301,643#

APPARATUS FOR WORKIHG'vS-HEET METAL Filed Feb. 11. 19:59 5 sheets-sheet 4 RMAN L By ALTER gORBTEMLB d: A orneqs:

E. SACHSE E1 L APPARATUS FOR WORKING s ET METAL Filed Feb. 11, l '-J vov. 1o. 1942;

5 sheets-sheep 5 /nve ors: ERNST QCHSE ROBERT KORT/NG HERMANN WoHL RAB WALTER o/asTEL Paiested Nv..1o, 1942 2,301,643 e APPARATUS Fon WORKING snEET METAL Ernst Sachse, Dessau, Robert Korting, Kochstedt near Dessau, Hermann Wohlrab, Dessau- Zlebigk, and Walter Borstel, Dessau, Germany; vested in the Alien Property Custodian Application February 11, 1939, Serial No.'255,91 0

8 Claims.

The present invention relates to an apparatus for working sheetl metal and particularly relates to apparatus for edging or flanging sheet metal.

Although not specifically limited thereto, the present invention `will be particularly described in connection with an apparatus for bending and flanging the edges of sheet metal pieces of irreg.

ular or curved outlines.

With pieces of sheet metal with irregular out'- lines, considerable dimculty has been experienced in properly fianging the edgesof the same.

Germany February 16, 1938 Where Athis ilanging has been. accomplished by i clamping the piece with the edge to be ilanged protruding, followed by hammering over such protruding edge with a hammer, there is a tendency for the' metal to fold due to resilient` shortening of the periphery thereof.

With irregular shapes or curves, this difficulty becomes very marked and considerable labor and skill of manipulation are required before a satisfactory flanged piece is produced.

kIn accomplishing this ilanging by machines having a pair of interchangeable adjustable forming rollers betweenwhich the edge of the plate or piece of sheet metal isA inserted, it is necessary to perform the flangingI by a repeated number of passes through or between the rollers with the plate being bentonly at a slight angle on each pass.

, Between each pass, it is necessary to readjust the forming'rollerspr even to replace such rollers until the desired angular flange is obtained but `with such rollers, it is only readily possible to apply this fianging procedure to pieces of circular or cylindrical contour, as for example,

cylindrical sheet metal bodies or the circular bot-` toms of containers, and so forth.

Furthermore, it has not been round most satisfactory to ange sheet metal pieces or plates by drawing proceduresv due to the expense of the dies, this drawing procedure being satisfactory and economical only where very large quantities of pieces of the same shape are yflanged.

It is among the 'objects of the present invention to provide improved apparatus for ilanging sheet metal edges; which are particularly applicable to plates or pieces of sheet metal having irregular, curved edges and which maybe accomplished without skillful manipulation and the minimum of laborl and the maximum economy in production. y

Another obj'ect is to provide an improved apparatus for fianging sheet metal pieces or plates:

which will not require the u se of expensive drawing or forming dies, which will not. require repeated passes through adjustable rollers and which will give a high production of flanged sheet metal objects without the necessity of skillful working to eliminate tendency toward folding because of the shortening of the periphery of the sheet metal as a result of the :Banging operation.

Other objects will be obvious or will become apparent during the course of the following specification. Y k In accomplishing the above objects, it has been found most satisfactory, according to the present invention, to bend successiveV portions of .the

edge of the sheet metal or plate to the desired angle and simultaneously therewith, or shortly thereafter, to subject such edges to substantially compressive forces sufiicient to upset said edges and eliminate any folding tendency.

In carrying out this method, it has been found most desirable to form aJ holder for thesheet of irregular or other contour to be flanged permitting the edge portion to protrude. 'This edge portion then may be flanged by a suitable die or ram to the final angle or in stages.

Following 'each bending operation, the flanged or bent edges are subjected to compression by an upsetting tool to eliminateany folds.

lThis compression device may be caused to act upon either. one or both sides of the flange during or subsequent to the formation of such flange and the operation of the flanging device may be effected by the same drive mechanism which actuates the device for bending or forming the ange.

during and subsequent to the bending operation.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings,

which illustrate preferred embodiments of the inventive idea.r

In the drawings:

Figures 1 to 3 show oneembodiment diagrammatically, Figure 1 being a side sectional view through thcenter of the device in starting position, Figure 2 being a similar view in theflnal position and Figure 3 `being' a transverse horizontal section upon the line III- III of Figure 2 upon an enlarged scale as compared to Figure 2.

Figures 4 to 6 show another embodiment, Fig- 4mechanism of Figures 4 and 5, upon an enlargedl scale as compared to Figures 4 and 5.

Figures 7 and 8 diagrammatically show still another embodiment in side view and in partial section, Figure 7 showing the position of the parts at the beginning oi' the operation, and Figure 8 showing the position of the parts at the completion ofthe operation.

Referring to the devices shown upon Figures 1 to 3, the machine frame I carries a table 2. The sheet of metal 3, the edge of which is to be ilanged, is carried by and clamped to the support plate 4, the edge to be flanged projecting beyond the edge oi the plate 4.

The projecting edge of the plate 3 is then brought into position along with the support plate 4 below the structural portion or abutment 5..

Below the support plate 4 is positioned a hollow cylindrical reciprocating ram member 6 which receives the compression coil spring 1. The ram member 6, at its lower end, receives the follower 8 carrying a roller which cooperates with a cam 9.

The cam 9 is fixed to and rotates with the shaft I0 which has bearings in the machine frame I.

Theshaft I 0 carries another cam Il next to the cam 9, which cam actuates a ram I2 having a contact roller, said ram I2 having an upper step portion I3 upon which step the projecting edge of the sheet metal element 3 to be flanged is supported.

The edge oi.' the step will abut the edge of the Asupport plate 4. Tl/ie action of the cam Il in moving the ram I2 upwardly to ange the projecting edge of the sheet metal piece 3 will be opposed by the compression spring I4 enclosed within a recess in -the frame I. 'I'he compressionspringmaintains the roller of ther-am I2 .45

in contact with-the cam II at all times.

'I he rain4 is also provided below the step I3 with a recess which receives the compression or upsetting tool I5 'which is shown on larger scale inl/Figure 3. In the upperposition of the ram I ated at'ffthe side of the ilanged' portion of the sheet'l metal piece 3.

The'shaft I Il also carries the cam I6, which is situated at a distance from the cam Ill and which actuates the roller of a ram I1, said ram I'I being guided by portions of the frame I.

The ram I1 reciprocates parallel to the rams 3 and I2 and the ram is normally its roller in contactv with the cam I 6 by means (shown in Figurer 2), the tool I5 is situpressed with ofthe compression coil spring I3 which at its presses against a portion of the 25 attached to themachine frame I and the spring 23 normally presses such arm 23 to the left (looking in the direction of Figures 1 and 2).

justed by the cap 21 which is threaded on to the outside of the sleeve 25.

Whenthe ram I1 elevates the joint I9, as shown in Figure 2, the spring 26 will act directly against the sliding element 22 and' through suchelement 22 upon the compression or upsetting tool I5. j

The upsetting tool I5 is provided with a pair of upsetting jaws 28 and 29 which arenormally pressed apart by an intervening spring member (see Figure 3).

The jaws 28 and 29 which have concave pressure faces cooperate with the jaws 30 and 3| having correspondingly shaped convex compression faces. The jaws 30 and 3l are also pressed' vapart by means of an intervening spring element. y

The jaws 30 and 3l are carried by the abuty:ment or extension element 5 of the machine frame so that the jaws 28 and 29 on theoutside ofthe ange and the'jaws 30 and 3| on, the inside of the flange will act substantially upon the same portion of the metal.

The outside oblique or sloping surfaces of the jaws 23, 29, 30 and 3I are received in bevelled recesses and slide upon the bevelled surfaces of these recesses in the receiver elements 34 and 35.

As a result, when the jaws 2s, 2c, 3u and 3| are pressed together, in addition to the coinpression forces tending to compress the flange.

there will also be horizontal forces tending tol bring the jaws together.

While the pressure forces cause a clamping of the metal sheet edge, the horizontal forces cause a movement of the jaws in a direction parallel to the edge of the metal sheet and thus cause an upsetting of the flanged edge of the metal Y sheet 3.

In operation, the sheet metal piece to be flanged is clamped to the support plate 4 placed .upon the shelf or table 2 and is then pushed for- 'ward until the frontl edge of the support plate 4 abuts the adjacent surface of the member I3.

At this point, the edge to be flanged will Le upon the top surface of the member I3.

Then the shaft I0 is caused to rotate and the ram 6 will irst be elevated pressing the plate 3 beyond the edge to be flanged rmly against the bottom of the abutment 5. Then, the ram I2 is elevated, and the edge portion of Ithe plate 3 is bent upwardly against the"vertica1 wall of the abutment 5 to the position indicated in Figure 2.

The ram I2 will continue to elevate until the upsettingtool I5 is positioned with its jaws 28 and 29 opposite thejaws 30 and 3|, as shown in Figure 3.

Then, the ram I'I is elevated and it elevates the pivot point I3 of the toggle, extending the toggle and causing the follower member 22 to press the upsetting tool I5 against the flanged portion of the sheet metal piece 3.

The pressure exerted will be the pressure of the spring 26 which is acting against the extended The pressure of the spring 23 maybe ad- 75 toggle arms 20 and'23.

This pressure will have the effect of drawing together the anged edge-and `also pressing it with the resultant upsetting thereof. As the shaft' I0 then continues to rotate, theffcams I6, II and 3 will cause the rams II, I2 and 5 to be-withdrawn successively from their uppermost position, shown in Figure 2, to the position of- Figure 1, releasing the'upset portion of the ilange and permitting the plate 4 and the sheetV 3 to be moved laterally on the table 2 to Vpermit the next edge spouses portion of the sheet I' to be flanged and upset in the manner just described.

In the embodiment of Figures 4 to 8, there is provided an upper die or reciprocating element Il and a lowerl fixed die element Il.

The element Il is provided with a contact plate II upon its lower face which serves for holding down the sheet metal I, the edge of which is to be iianged, which sheet metal l is carried by the support plate I.

'I'he plate I carries a guiding pin I2 vprojecting into a corresponding groove Il of the lower die Il and used for theguiding oi the sheet 3 and the plate I uponthe die element Il.

The pressure plate II is attached by the threaded pins Il tc the upper die III. The pins II are encircled by coil springs Il situated in recesses provided iri the upper die Il. The enlarged head I1 of each pin Il fits in a separate recess I8. When the die I is raised, the springs I8 maintain the plate II at a distance from the lower surface ot the die Ill. The heads I1 striking ythe bottom of the recesses II-will limit the disi tance by which the pressure plate II may be moved away from the upper die I0 by the compression springs Il.

In a semi-circular recess in the upper die II, as best shown in Figure 5, are positioned the jaws II and li. the upper faces of which are ci'rcular so as closely to ilt into the circular recess and to be movable therein. -.gg

The two jaws l0 and li are mounted upon the -pivot pin 52 so that they may swing toward and away from each other. The pivot pin l1 is mounted on a plate Il which is connected by screws I to the upper die member Ill.

Those portions of the jaw members 5l and 5I, which are situated below the pivot 52, project beyond the lower surface oi the upper die Iii. The

- jaw members Il and lil have extension portions li and Il respectively, which are normally pressed apart by the spring Il which spring is located below the pivot element 52.,I The extensions Il and l2, asbest showninFigure 5, are received'in the recesses having the bevelled faces l I3' and II which tend to press the lower extensions I I, and I! and the lower portions of the jaws II and Il together against the action. of the spring Il upon lowering of the upper die element Il. 1 j

The lower die element Il receives in a circular recess, an inside pair oi' upsetting jaws Il and II, the outside surfaces of which are of cylindrical shape. These jaws are shown in perspective removed from the assembly of Figure 5 in the lower part of Figure 8.

These jaws ll and II are held in position by means ci the plate Il (see Figure 4).

'I'he top surfaces ofthesejaws II and BI are in the same plane as the top of the lower die element Il. i a

Av compression spring Il, inserted between the jaws Il and II, tends to spread these jaws apart. Those surfaces of the two'pairs of jaws, which are situated opposite each other at the end of a velement I0 and a movement of the extensions Il and I2 toward each other along the bevel surfaces I3 and II, the extensions II and I'l will be pressed together moving the lower portions of the position by the spring Il after each' stroke of the l press.

In operation, when the die elements Il and Il move toward each other, after the sheet 3 has been placed upon the plate I. as shown in Figure 4, the pressure plate II will tlrst contact the sheet metal piece 3. The spring It will then be pressed until the plate II contacts the bottom' of the l .lill

, tions about the pivot 52.

the extensions Il and I2 of the upper jaws Il and upper die element, whereupon the jaws Il and Il will press down the projecting edge of the sheet metal l against the outside faces of the inside jaws Il and 58. The bent edge of the sheet l will be brought between the opposed front surfaces of the two pairs or jaws 50, 5I and 5I, it. At the same time, the lower bevel edge of the plate 53 attached'to the upper die II, will contact with the adjustable bevel surface 1I of a member carried by the lower die Il. This contact will tend to press the lower end of the plate Il with the jaws l0 and 5| inwardly against the flanged edge portionof the sheet of metal 3.

As this occurs, the jaws BI and Il will press against the jaws 55 and and at the same time, the jaws will tend to move together because of the downward sliding movement of the extensions Il and 82 of the upper jaws lll and ll upon the bevel faces Il and II. Thus the pairs of jaws carry out oscillatory movements in opposite direc- BI engage the projections II and I1 of the lower jaws 55 and Il and compel them to carry out the same oscillatory movements. The opposed ribbed front surfaces of the two pairs of jaws transmit this movement to the edge. of the metal sheet 3 with the result that the flanged edge portion will be upset, giving the same effect as obtained already in the embodiment of Figures l to' 3.

'I'he bevel surface 'III is adjustable by means of the adjusting screw II, so that the pressure may be regulated and the device may be adapted. to different thicknesses of the sheet I.

In the third alternative construction shown in Figures 7 and 8, a pairof upsetting tongs is provided which is more fully described in IGerman Patent No. 500,811. y

In thisembodiment the sheet ofl metal I is clamped between thesupport plates I and 'I' Then, this combination is clamped between the s1llilvrting table l2 andthe .holding device 1l which is reciprocably mounted in the machine frame 1I and pressed down by an encircling coil spring 1I.

This upper holder member 'IS has a step "Il which contacts the inside vedges of the upper supportv plate I. The inside edge of the lower support plate I' serves as the bending edge or as the pivot upon which the flanging takes place.

The upsetting tongs are mounted upon the reciprocatingstructural element 11 which is provided with aguide Il and which may be moved longif tudinaliy in a direction of the plane of the edge of the sheet metal piece One leg 1l of the pair of tongs is rigidly mount l ed on the body 'I1 while the other leg 'I0 ispivotally mounted at Il. .The two tong elements are normally separated by the intervening leaf spring 82 as long as pressure is not applied to the upper tong element 1l. t

As shown in Figure 5.

The upper leg 18 is normally operated by the lever 83 which is pivotally mounted at 84 upon the structure 11 and has a projection 85 carrying a roller engaging the upper tong element 18 to press it against the lower fixed tong element 1 8.

As described in the German Patent No. 500,811, the two tong elements may enclose pairs of jaws engaging bevelled surfaces provided in the tong elements.

Upon movement of the arm 83 downward in the direction indicated by the arrow. the two tong elements 18 and 18 will rmly grasp the edge of the plate 3 to bend said plate around the edge of the lower support plate 4' and also will compress and draw together such bent edge so as to produce the upsetting action in a direction perpendicular to the plane in which the tong elements move.

As indicated in Figures '1 and 8, when the lever 83 is moved downwardly from the position of Figure 7 to the position of Figure 8, the support element 80 is guided in its movement by the swinging linkage arrangement 84, 85, 88, 81 which is connected to the machine frame 13 and forms a parailelogram. Thus the element 88 swings about the bent edge of the sheet 3 soas to give proper movement to the tong elements 18 and 18. It will be noted that the swinging bars 84 and 85 are mounted upon the machine frame 13 by the pivotal connections 88 and 88, the line connecting the axes of the pivot mounts 88 and 88 extending through the bending edge of the sheet of metal 3.

As th'e support element 80 is moved downwardly by the lever 83 in the, direction indicated by the arrow in Figure 7, it extends-a spring 88 which is connected to the joint between the links 85 and 88 by the pin 8| and to the frame 13 by the pi'n 82, The spring 88 tends to move these parts in a `position in which the structure 11 is in engagement with the stop 83, so that the upward movement of the structure 11 is limited by the upper stop pin 83, while the outward movement of the f lever 83 is limited by the stop pin 83. The lever 88 not only starts theswinging movement but is also used to actuate the tongs 1l and'18. 'i

The downward movement of the structure .T1-88 is limited by the adjustable' Stop philv 98 which may be placed in the various openings 88. depending upon the angular flange .which it is tong elements 18 and 18 to grasp the projectingV edge oi' the sheet metal plate 3 following which the structure 80 will swing out together with thej structure 11, as the lever 83 is moved downwardly.

Continued movement of the lever 83 will bendv the edge of the sheet metal 3 from the position of Figure 7 to. the position of Figure 8, untillthe guide structure 88 contacts the adjustable pin 88. Any additional force at this point lupon the lever 83 will press together the flanged edge of the plate 3 accomplishing the result already described in connection with the embodiments of Figures 1 to 6.

After termination of the bending and upsetting operations, the hand lever 83 may the be ele'- vated until the stops 83 and 83' will limi further upward movement.'

aan this point, the spring a2 win ep'n the tong elements 18 and 18 and the elements 18 and 18 may be moved outwardly along with the structure element 11 which slides in the guide element 88.

The spring 88 during this operation eilects return of the entire swinging mechanism until the structural portion 11 strikes the pin 83. Then, to move the edge of the sheet 3to the next position to be hanged, the foot lever 88 is pressed down releasing the presser element 15 and permitting movement ofthe sheet 3 to the next position. Theoperation may then berepeated, the'jaws engaging that portion of the sheet 3 K which is adjacent to the one treated.

It is apparent that the speciiic illustrations shown above have been given by way of illustrationv and not by way of limitation and that the structuresabove described are subject tovwide variation and modification without departing from the scope or intent of the invention, all of` whichKvariations and modifications are to Abe included within the scope of'the'present invention.

prising two die elements movable relatively to each other to clamp a sheet of metal and to bend an edge portion thereof, each' of said die elements d comprising jaws, neans connected with said Jaws for casing them to operate as an upsetting tool desired to obtain. 'I'he stop pin 88 is used to 4 eacho rod 81 to the lever 85 which reacts against the V enlargement 88' on the presser element 15 to elevate said presser element against the force of the spring 14. Y

The body 11 must be so adjusted prior to operation that the edge of the plate 3 is situated between the tong elements 18 and 18.

Then the presser element 15 is released by the foot pedal 88 and the presser foot 15 is permitted to move down so that its projection 18 will cohtact the edge of the plate 4.

Then, the lever 83is'moved downwardly in the direction ofl the arrow (see Figure' 1). This downward movement will cause the jaws of the and upset the bent portion of the metal sheet,

and means connected with the mst-mentioned means to.actuate the first-mentioned means close to the end of the clamping movement of the die elements.

2. -An apparatus for working sheet metal comprising two die elements movable relatively to er to clamp a sheet of metal and to bend an ed e portion thereof, each of said die elements comprising a pair of jaws, and means connected with said laws for causing th'e `iaws of each pair to move relatively to each other in the direction of said edge portion and to move toward each other close to the end of the clamping movement of the die elements, thereby upsetting the bent portion of the metal sheet.

3.v An apparatus for working sheet metal comprising two die elements movable relatively to each other to clamp a sheet of metal and to bend an edge portion thereof, each of said die elements comprising -a pair of jaws, each of said Jaws being substantially at and -having 'substantially the iorm oi' a cylindrical sector having a frnt surface adapted `to engage the metal sheet, the front surfaces' of two jaws constituting a pair being situated one opposite the other, pivots carried 'by the die elements and rotatably supporting said jaws, and means engaging said jaws to cause them to operate as an upsetting tool and upset the bent portion of the metal sheet.

4. An apparatus for working sheet metal comprising a. pair of tongs, a structural element carrying said pair of tongs, a guide supporting said Y structural element, said structural element being movable along said guide, said pair of tongs being adapted to clamp an edge portion of a sheet of mei-al, means supporting said sheet of-metal and comprising a bendingedge, and means connected with said guide for causing lsaid guide, said structural element and said pair of tongs to swing about said bending edge to cause said pair of tongs clamping said edge portion of the sheet of metal to bend it over said bending edge and to upset it.

5. An apparatus for working sheet metal comprising a pair of tongsa structural element carrying said pair of tongs, a guidey supporting said structural element, said structural element being movable along said guide, said pair of tongs being adapted to clamp an edge portion of va sheet of metal, means supporting said sheet of metal and comprising a bending edge, a lever pivotally supported by said structural element and having a member engaging said pair of tongs and causing said pair of tongs to clamp said edge portion of the sheet of metal', a leverage system connected Awith said guide and causing said guide, said structural element and said pair of tongs to swing about said bending edge to cause said pair of tongs clamping said edge portion of ythe shee't of metal to bend it over said bending .edge upon the further actuation of said lever, and a stop limiting the swinging movement of said guide, said structural element and said pair of tongs, a further pressure against said lever after the completion of said swinging movement being transmitted to said pair of tongs and causing an upsetting of the bentportion of the metal sheet to eliminate foldingthereof.

6,. Anapparatus for edging sheet metal of irregular and curved outlines, said apparatus comprising, in combination with an upsetting tool for upsetting a bent edge of a metal sheet to eliminate folding thereof, single means supporting said tool and engaging said edge to bend the same, and' means connected with said supporting and bending means for moving' thesame rto bena said edge and simultaneously move said upsetting tool into'an operative position in engagemcnt with said edge.

7. An apparatus for edging sheet metalof irregular and curved outlines, said apparatus lng thereof.

8. An apparatus for edging sheet metal of irregular and curved outlines, said apparatus comprising,I in combination with an upsetting tool for upsettinga bent edge of a metal sheet to eliminate folding thereof, a supporting table having a bending edge, a holder member movable perpendicularly to the supporting surface-of the supporting table, a spring pressing said holder member against the metal sheet lying upon said supportingsurface to clamp said sheet,

single movable means .supporting said tool and engaging said edge to bend the same, said means being movable to bend said edge and simultaneously move said upsetting tool into an operativeA position in" engagement with said edge, and driving means movingvsaid supporting and bending means and raising said holder member from .said metal sheet after the bending and upsetting of said edge thereof.

- ERNST SACHSE.

ROBERT KORTING. HERMANN WOHLRAB. WALTER BORSTEL. 

